'Congregation of the Lord' in the Bible

“Thus says the whole congregation of the Lord, ‘What is this unfaithful act which you have committed against the God of Israel, turning away from following the Lord this day, by building yourselves an altar, to rebel against the Lord this day?

Is not the iniquity of Peor enough for us, from which we have not cleansed ourselves to this day, although a plague came on the congregation of the Lord,